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The Analysis of Closed-form Solution for Energy Detector Dynamic Threshold Adaptation in Cognitive Radio
(Společnost pro radioelektronické inženýrství, 2017-12)
Spectrum sensing is the most important process in cognitive radio in order to ensure interference avoidance to primary users. For optimal performance of cognitive radio, it is substantial to monitor and promptly react to ...
Effect of Location Accuracy and Shadowing on the Probability of Non-Interfering Concurrent Transmissions in Cognitive Ad Hoc Networks
(Společnost pro radioelektronické inženýrství, 2013-12)
Cognitive radio ad hoc systems can coexist with a primary network in a scanning-free region, which can be dimensioned by location awareness. This coexistence of networks improves system throughput and increases the efficiency ...
Improved Energy Detector for Wideband Spectrum Sensing in Cognitive Radio Networks
(Společnost pro radioelektronické inženýrství, 2014-04)
In this paper, an improved energy detector for a wideband spectrum sensing is proposed. For a better detection of the spectrum holes the overall band is divided into equal non-overlapping sub-bands. The main objective is ...
Sensing Task Allocation for Heterogeneous Channels in Cooperative Spectrum Sensing
(Společnost pro radioelektronické inženýrství, 2010-12)
In the traditional centralized cooperative spectrum sensing, all secondary users sense the same channel. But, for a given channel, there exists detection performance diversity among all the users, due to the different ...
Optimum Detection Location-Based Cooperative Spectrum Sensing in Cognitive Radio
(Společnost pro radioelektronické inženýrství, 2010-12)
Cognitive radio arises as a hot research issue in wireless communications recently, attributed to its capability of enhancing spectral efficiency and catering for the growing demand for bandwidth. As a good embodiment of ...
Impact of Power Allocation and Antenna Directivity in the Capacity of a Multiuser Cognitive Ad Hoc Network
(Společnost pro radioelektronické inženýrství, 2012-12)
This paper studies the benefits that power control and antenna directivity can bring to the capacity of a multiuser cognitive radio network. The main objective is to optimize the secondary network sum rate under the capacity ...
Robust Resource Allocation for OFDM-based Cognitive Radio in the Presence of Primary User Emulation Attack
(Společnost pro radioelektronické inženýrství, 2012-12)
Cognitive radio (CR) is a promising solution to improve the spectrum efficiency in which some unlicensed users are allowed to exploit frequency bands which are not used by licensed network. However, CR technology imposes ...
An Efficient Filter Banks Based Multicarrier System in Cognitive Radio Networks (invited paper)
(Společnost pro radioelektronické inženýrství, 2010-12)
In cognitive radio techniques, OFDM is usually regarded as the physical layer candidate. However, the weaknesses of the OFDM technique, i.e., using plain FFT for spectral analysis , decreased bandwidth efficiency due to ...
A Broadband High Gain Circularly Polarized Antenna System for Cognitive Radio
(Společnost pro radioelektronické inženýrství, 2020-09)
This paper proposes a broadband high gain LHCP (left hand circular polarized) antenna system using a microstrip line fed slot antenna, reflecting surfaces, and linear polarization (LP) to circular polarization (CP) transformer ...
Performance of a Cognitive Relay Network under AF Relay Selection Scheme with Imperfect Channel Estimation
(Společnost pro radioelektronické inženýrství, 2016-06)
In this paper outage performance of a secondary user (SU) is evaluated under amplify and forward (AF) relay selection scheme with an imperfect channel state information (CSI)while sharing spectrum in an underlay cognitive ...